Regulators in the USA are reviewing adverse events of liver injury in patients taking the weight loss drug orlistat, marketed under prescription by Roche as Xenical and sold over the counter by GlaxoSmithKline as Alli.

The US Food and Drug Administration says that between 1999 and 2008, the agency received 32 reports of serious liver injury in patients taking orlistat and of those cases, 27 were hospitalised and six resulted in liver failure. Thirty of the adverse events occurred outside the USA and the most commonly reported cases included jaundice, weakness and stomach pain.

The FDA added that it is reviewing additional data submitted by Roche and GSK on suspected cases of liver injury. Noting that “the issues here are complex”, the agency stressed that “no definite association between liver injury and orlistat has been established at this time”. People taking Xenical and Alli should continue to use the products as directed.

Debbie Bolding, a spokeswoman for GlaxoSmithKline told the Associated Press that there is no evidence Alli causes liver injury, noting that it primarily acts on the intestinal tract. She said its safety has been studied in over 30,000 patients in 100 clinical studies.

"Liver changes can have many causes," Ms Bolding added, noting that “people who are overweight and obese are predisposed to liver-related disorders”. GSK sales of Alli reached $125 million in the second quarter while Roche revenues of Xenical for the first half of 2009 reached 209 million Swiss francs, about $197 million.

Advair stolen in USA
Meantime, GSK has issued a warning, saying that two lots of the company’s asthma and chronic obstructive pulmonary disease blockbuster Advair (salmeterol and fluticasone) Diskus were stolen on August 2 from its distribution facility near Richmond, Virginia, USA.

Some 25,600 units have been stolen and although GSK did not put a price on the value of the drugs lost, it is thought to be in the region of $5 million. The company said that the medicine in the stolen cartons “could represent a health risk because it has been removed from the legitimate supply chain and the storage conditions under which the stolen products were held are unknown”.